Understanding our cryosphere through Earth observation satellites

Q. How does Earth observation contribute to our understanding of the melting cryosphere?

Christian Hauglie-Hanssen: With Earth observation, we use satellites that go in what we call a polar orbit, meaning they pass over the Arctic and the Antarctic. To record data relevant to climate change, satellites have different types of instruments such as radar and optical sensors to record changes on the ground or in the atmosphere. Satellites are very powerful in that they have been able to record Essential Climate Variables such as ice sheets, sea ice, snow extent, which are indicators of climate change.

Over the past century, there have been polar expeditions to conduct in situ measurements and data in the Arctic region. However, there are things satellites provide that you cannot obtain simply by measuring on the ground. One of the major benefits of satellites is that you can rapidly re-visit areas by flying over and recording data several times per day. They can monitor vast areas and provide continuous data series, allowing us to understand trends and changes over time. In order to get a good understanding of the processes and the changes to the climate and the cryosphere, we really need to have these data tracks over time – over decades, actually. Sometimes satellites complement in situ measurements. Sometimes they're unique because they can cover vast areas and over long time periods.

We want to create awareness around how powerful Earth observation satellites are. It’s important to continue to invest in these capabilities, not for the sake of putting satellites into orbit, but for the sake of being able to ensure these long timespans of continuous data flowing into science, policy making and local action.

Q. The Norwegian Space Agency is contributing to better monitoring of permafrost thaw, could you speak about these efforts and recent developments in this field?

Christian Hauglie-Hanssen: Earth observation data, in our view, are really instrumental, because they are providing something unique in terms of monitoring the melting cryosphere. We participate in the European Union Space Programme and are a member of the European Space Agency, where we participate in the program boards and define specifics of these satellite missions. What Norway has contributed with specifically is, for instance, the development of a service relevant for the thawing of the permafrost, which is a hard thing to do. We know that the effects of permafrost thaw such as methane and CO₂ emissions, which are very strong contributors to climate change. A specific topic that has been addressed in Norway is what we call ground motion services, which means that we can monitor the thawing of the permafrost by proxy. We can see that you have a shift in the actual level of land by millimeter precision over time. We're using radar satellites, and by monitoring over time and using different techniques, we can actually measure the thaw. Norway and the Norwegian Space Agency together with our the Geological Survey of Norway developed this as a service. Norway is monitored by several billion data points in the high north in particular. In the northern part of the Nordic countries, including Svalbard, we can support the measurements of these changes in permafrost, which is exceedingly important in terms of seeing the actual effects of this thawing. And by that, you could deduce the sources and the effects on methane and CO₂ emissions, for instance.

Q. Ice sheets, sea ice and snow are recognized as Essential Climate Variables. Could you explain what this means and how data on these variables is improving our understanding of climate change?

Christian Hauglie-Hanssen: Essential Climate Variables (ECVs) critically contribute to the characterization of Earth’ s climate. The ECVs are defined by The Global Climate Observing System (GCOS) and are required to support the work of the UNFCCC and the IPCC. Research and Development work in Norway in the framework of the European Space Agency Climate Change Initiative and Copernicus has resulted in data and services responding to ECVs and early warning systems for floods and storm-surges.

The data sheets of the ECVs, which include sea ice, snow and so on, provide empirical data in terms of attributing climate events to specific causes. What we’re targeting is the actual risk of climate changes, and how to guide mitigation and adaptation measures. The Global Climate Observing System defines 55 of these essential climate variables, and about 60% of them are observed via satellites. Satellites have become a very powerful tool in terms of measuring and verifying the effects of these changes.

Q. What role does earth observation play in mitigation and adaptation efforts addressing changing climate?

Christian Hauglie-Hanssen: The climate changes we’re seeing are quite severe. I think what is essential here is looking at which parameters and which changes have the most severe effects on people in the Arctic. It could be rockslides, erosion, avalanches, changes to the groundwater content, risk for wildfires and so on. The role that Earth observation can play, in my opinion, is providing information that could help maintain the quality of living and ways of operating in the Arctic. One important aspect is the actual need for relocating communities. We are seeing in Svalbard that the permafrost is thawing, which means that some of the buildings that have been residing on the permafrost need to be - and they are being - relocated now because the ground is melting. The role that Earth observation will play in that is providing the ability to do more long-term planning and to implement adaptation efforts such as how to protect these areas and how to relocate. Infrastructure is critical for maintaining a well-functioning society.

Q. How can data become even more reliable in future, to assist people on the ground who are navigating the effects of a changing Arctic?

Christian Hauglie-Hanssen: In terms of becoming even more reliable, I think it's important to look at the more general trends in technology and the types of observations that you can do. We are investing in new technology, new services with more precision, more satellites, and higher revisit rates. Currently, there are three new satellites being built that focus on the cryosphere. They're using more enhanced instruments and will be able to measure different variables that are a supplement or a complement to existing capacities. While these satellites are complex and costly, they do have a limited time life, typically between eight to 10 years. That gives you a natural timeline where you can plan for the next satellites where you can increase and enhance their capabilities.

In Norway, we are building specific satellites for monitoring maritime traffic. We're seeing now with changes to sea ice and more severe weather, for example, these satellites help with the national operations of our maritime traffic. The coast of Norway and around Svalbard are the most densely trafficked area in the Arctic region. These satellites can serve in the provisions of safe maritime operations, also in the Arctic.

In August, we launched the Arctic Satellite Broadband Mission, which are two satellites that are providing broadband coverage in the Arctic for the first time to regions that didn’t previously have it. To have communication capabilities in the Arctic that was not there before is important in terms of developing society, promoting safe operations and being able to do research. This provides increased security to Arctic inhabitants, ship traffic, and researchers that work there.

Q. How can data from Earth observation be applied practically?

Christian Hauglie-Hanssen: This is a central issue, because you can record as much as you want, but you haven’t really obtained much until the data is refined and handed to the end user. There are several elements to this. First of all, a huge amount of data is put to use in generating models, verifying atmospheric changes and so on. But there are also data being archived, which means you could actually use them in different ways and extract more of the benefits from that data. It’s important to have a value chain and think, how can you extract the added value from the data to a format that is useful for scientists or, perhaps local governments? One example of this is what I mentioned earlier with Svalbard, where infrastructure is being re-located due to permafrost. The data can be used to make a forecast and implement more informed area planning such as looking at areas of erosion you should stay away from. This is something that is concrete and is actually being applied as we speak. But this is something we are always working on to be more efficient in order to support actions that are already being taken.